Fowler, 35, injured himself while sprinting into second base on an attempted forceout in Friday's game against the Toronto Blue Jays in Dunedin, Florida. Fowler beat the throw from Blue Jays shortstop Bo Bichette and didn't slide, prompting him to arrive awkwardly and crumple to the ground in pain.
The Angels initially diagnosed Fowler with a sprained left knee, but a follow-up MRI revealed that it was far more serious. The team said Fowler is expected to need six to nine months to recover after surgery.
"Comeback season has commenced," Fowler said Sunday. "The cards I've been dealt, so you've got to deal with them and go at it like that."
Fowler, who is set to be a free agent after the season, doesn't think the injury is career-ending.
"I want to continue to play," he said. "I think I've still got a lot left in the tank. Right now I just want to get the knee back right and get going again."
Angels manager Joe Maddon said he plans to replace Fowler with Juan Lagares and Jose Rojas, the latter of whom is currently serving as a utility infielder. Before Sunday's game against the Blue Jays was postponed due to rain, Rojas had been slated to start at third base in place of Anthony Rendon, who was dealing with soreness in his left groin that resulted from a throw Saturday.
Fowler, acquired from the St. Louis Cardinals in early February, was 5-for-20 with six strikeouts to begin the 2021 season and has batted .218/.320/.370 over the past three years. But Maddon, who previously managed Fowler with the Chicago Cubs, said he believed the outfielder was just starting to get going offensively and will miss his presence on the team.
"He's one of those glue guys, man," Maddon said. "He really makes a difference. He does. You talk about it all the time with clubhouse guys, but this guy really is one."
Fowler's injury creates an immediate opening for the Angels' two most promising young players, Jo Adell and Brandon Marsh, both of whom are working out at the team's alternate site in Tempe, Arizona, before the minor league season begins. Adell struggled as a rookie last year, and Marsh has yet to play above Double-A after spending the coronavirus-shortened 2020 season playing mostly intrasquad games.
Maddon said he would defer to the Angels' minor league development staff on when Adell and Marsh are major league ready.
"It's hard for me to imagine that they've tightened up their game [from spring training] to the point where you want to bring them up yet," Maddon said.
The Associated Press contributed to this report.